NTRK Gene Fusion Detection in Atypical Spitz Tumors.

Atypical Spitz tumors (AST) deviate from stereotypical Spitz nevi for one or more atypical features and are now regarded as an intermediate category of melanocytic tumors with uncertain malignant potential. Activating NTRK1/NTRK3 fusions elicit oncogenic events in Spitz lesions and are targetable with kinase inhibitors. However, their prevalence among ASTs and the optimal approach for their detection is yet to be determined. A series of 180 ASTs were screened with pan-TRK immunohistochemistry and the presence of NTRK fusions was confirmed using FISH, two different RNA-based NGS panels for solid tumors, and a specific real time RT-PCR panel. Overall, 26 ASTs showed pan-TRK immunostaining. NTRK1 fusions were detected in 15 of these cases showing cytoplasmic immunoreaction, whereas NTRK3 was detected in one case showing nuclear immunoreaction. Molecular tests resulted all positive in only two ASTs (included the NTRK3 translocated), RNA-based NGS and real time RT-PCR were both positive in three cases, and FISH and real time RT-PCR in another two cases. In seven ASTs NTRK1 fusions were detected only by FISH and in two cases only by real time RT-PCR. The frequency of NTRK fusions in ASTs is 9%, with a clear prevalence of NTRK1 compared to NTRK3 alterations. Pan-TRK immunohistochemistry is an excellent screening test. Confirmation of NTRK fusions may require the use of different molecular techniques.

A Rare Case of Hydrocystoma of the Labial Commissure: Histopathology and Clinical Picture.

OBJECTIVE: Hydrocystomas (HCs) are rare, benign, skin adnexal cystic tumors that may be either eccrine or apocrine. BACKGROUND DATA: Apocrine-HCs are cystic lesions that arise from the apocrine secretory coil, whereas eccrine-HCs are retention cysts of the eccrine duct. The commonest site is around the eyes, on the ears, scalp, chest, shoulders, or feet; HCs of the oral cavity are very rare. METHODS: The case is reported of a 36-year-old man with a nodular lesion that was 7 × 5 mm in size on the labial commissure. The lesion was treated in direct contact with a diode laser that was 980 nm in continuous wave mode, with a 320 µm fiber at 1.8-2.0 W of power. RESULTS: Complete healing occurred within 15 days. There were no adverse effects. The patient was carefully followed up, and there has been no recurrence. Histopathologically, the lesion was a multilocular cyst lined with a single-, and in some areas a double-layered epithelium with eosinophilic cytoplasm. Immunohistochemically, the secretory epithelium was positive for S-100 protein and negative for cytokeratin 5/6. CONCLUSIONS: The histopathological and immunohistochemically diagnosis was of eccrine HC. The report stresses differential diagnosis versus cystic lesions of the labial commisure.

The Role of Fine Needle Aspiration of Orbital Lesions: A Case Series.

OBJECTIVE: This paper analyzes a series of ultrasound (US)-guided orbital fine needle aspirations (FNAs) which provide diagnostic information that cytopathologists approaching orbital lesions for the first time can find useful and underlines the importance of teamwork. STUDY DESIGN: The investigators retrospectively obtained data from 24 consecutive orbital FNAs. For all patients, a complete clinicoradiological database was created. FNAs were performed under US guidance with 25-gauge needles and an aspiration biopsy syringe gun, and sent to the Department of Pathology for examination and data management. RESULTS: The mean age of the patients was 54 years. Imaging studies included US, magnetic resonance imaging and computed tomography scans; 9 lesions involved the right orbit and 15 the left orbit. The mean lesion size was 23.6 ± 7.2 mm. After microscopic examination, 7 smears were labeled as 'nondiagnostic', while in 17 cases a definitive diagnosis was proposed, which always proved to be correct (70.8%, specificity = 100%). CONCLUSIONS: The investigators believe that FNA biopsy of orbital masses is a necessary step; its weaknesses lie in the particularly delicate site of sampling and the extreme heterogeneity of lesions. Nevertheless, when orbital FNA is performed within a well-coordinated multidisciplinary team, it is a powerful tool that can be used to define the most appropriate management of these patients.

A rare case of synovial chondromatosis of the inferior TMJ compartment. Diagnosis and treatment aspect.

AIM: Synovial Chondromatosis (SC) is a rare, benign non neoplastic arthopathy characterized by the metaplastic development of cartilaginous nodules within the synovial membrane. In only 3% of all cases does it affect the temporomandibular joint (TMJ) and cases that arise from the lower compartment are rarely found in literature. The aim of this paper is to report a new case of SC of the inferior TMJ compartment with the description of the clinical, therapeutic and histopathological findings. CASE REPORT: This article presents a 68-year-old woman with preauricular swelling on the right side, pain, crepitus and limited joint motion. This patient was evaluated by preoperative clinical manifestation, CT scan and MR images. Both showed multiple, calcified loose bodies in the inferior compartment. Based on these images as well as the patient's signs and symptoms, a surgical intervention was performed. A good functional recovery with no signs of recurrence at 36 months of follow up was obtained. CONCLUSION: Among cases of synovial chondromatosis in literature, only twelve originating in the lower compartment have been reported, this one included. In all the cases treated for SC in the lower compartment, both in literature and in our case report, surgical treatment led to healing.

Clinical and histopathological profile of primary or secondary osteosarcoma of the jaws.

Osteosarcoma of the jaw is a rare disease; we report two cases, one in which the primary osteosarcoma had occurred in the sacrum and ileum, the second at the mandible. Dissemination of osteosarcoma to other organs, especially early dissemination to the lung, is common, but metastasis to the jaw has only rarely been reported. About 10% of osteosarcomas occur in the head and neck, most in the mandible or maxilla. Clinically, both patients presented swelling, and pain at the jaw in the premolar-molar region. At radiography, extensive bone erosion and soft-tissue swelling were apparent. A biopsy was taken and a diagnosis of osteosarcoma rendered in both cases. Histological examination revealed a proliferation of atypical osteoblast-like cells with hyperchromatic nuclei and formation of scattered neoplastic osteoid tissue. Immunohistochemistry for a panel of antibodies showed strong positivity for CD99, weak positivity for S-100, but was negative for desmin, vimentin, and cytokeratins. The diagnosis for both cases was of osteogenic osteosarcoma, chondroblastic subtype. Unfortunately, both patients died, one before the planned chemotherapy regime could begin, the second during the chemotherapy course. Our report aims to highlight the importance of the diagnostic profile in formulating a diagnosis of osteosarcoma, and that this tumor, although very rare, may be primary or may metastasize to the jaws.

Epithelial-myoepithelial carcinoma of the minor salivary glands: immunohistochemical and morphological features.

AIMS: Epithelial-myoepithelial carcinoma (EMC) is a rare malignant salivary gland neoplasm that most commonly occurs in the parotid gland, but can also arise in the minor salivary glands. Three cases are reported of epithelial-myoepithelial carcinoma of the minor salivary glands, with the goal of better defining this entity. PATIENTS AND METHODS: All three cases showed a characteristic nodular/multinodular growth pattern and classic biphasic tubular histology. All parts of each tumor were surrounded by a myoepithelial cell rim and there was evidence of invasion. RESULTS: Immunohistochemical analysis showed the tumor cells to be weakly positive for S100, cytokeratin (CK) CK5/6, CK7, CKAE-1/AE-3 and strongly positive for epithelial membrane antigen (EMA) and p63; they were focally positive for calponin and acute lymphoblastic leukemia antigen (CD10). The tumor cells were negative for vimentin, alpha-smooth muscle actin (SMA) (except one case), glial fibrillar acid protein (GFAP) and MIB1. The tumors were resected completely with wide margins and no recurrence or metastasis had occurred from 6 to 15 months after surgery. CONCLUSION: Three cases of minor salivary gland tumors are described and the differential diagnosis underlined in relation to benign myoepithelioma. The characteristic morphological and immunohistochemical features aided diagnosis of these biphasic tumors.

Perianal condyloma-like lesions in multiple myeloma associated amyloidosis.

Systemic types of amyloidosis include those associated with plasma cell dyscrasia, as in multiple myeloma. Here we describe a 57-year-old woman who was diagnosed as having multiple myeloma IgG lambda. Six months after the diagnosis of myeloma, mucocutaneous lesions began to develop, with ecchymoses in the body folds and eyelid and periorbital purpura. Pedunculated condylomatous tumours began to develop in the perianal area. The excisional biopsy of a perianal nodule revealed a faintly eosinophilic, amorphous material replacing almost the entire dermis, in association with ectatic, endothelial-lined vascular spaces. The dermal deposits showed affinity with Congo Red stain. There were no histopathological features typical of condylomata acuminata. A diagnosis of cutaneous myeloma-associated amyloidosis was established. To our knowledge, this is the second reported case of condyloma-like perianal lesions in multiple myeloma-associated amyloidosis.